Precision measuring tool



P. J. BAUERLE PRECISION MEASURING Tool.

Filed Feb. 3, 195o f4/47- role/wry April 29; 1952 LITlJ f )1111]3] QM ya gy/ .lg/x 176 97 610 1716 Patented Apr. 29, 1952 UNITED sTATEs PATENT OFFICE 227,594,844 .PRECISIQN rmAsURlNG Tool.

vPaul J ohnauerle, Flushing, N. Y.

Application' February 3, 1950, 'SeriaPNa$142,303`

'5 .Claims. (Cl. 33--1112`l special .instruments have 'been found to `permit inaccuracies of measurementl through human error or by fineparticles of dust invisibly clinging to the measuring surfaces thereof.

'Thehuman error 'is usually introducedby failureo'f the eyes to observe the closeness of the manufactured part to the measuring member. Considering the caliber of the'tolerances, it 'is readily apparent that the tool must include features which assist the eyes of the user in determining the accurate function thereof. It is to-- Ward V,this end that the instant invention is di.; rected and therefore a principal object thereof resides in the provision of means whereby the proximity of a manufactured part to a measuring T-square can be readily ascertained by the presence or absence of light therebetween.

Another object provides for means that will materially reduce the possible presence of dust on 4the measuring surfaces of the square.

A `further object provides forvan improved tool Whichmaybe employed either as an inside croutside square.

Another object provides for means whi-ch will eliminate undesirable reflected light.

Other ancillary objects will 'be apparent from the following detailed description, in which:

Fig. 1 is a front elevational view of the invention.

Fig. 2 is a side elevational view of a square ililustrating in dotted lines the blade locking mechanism.

Fig. 3 is a fragmentary perspective View of the square.

Fig. 4 is a fragmentary front elevational view of the invention and the surfaces of a machined or handmade part being checked thereby.

Figs. 5, 6 and 7 are fragmentary sectional views of alternate embodiments of the dust catching grooves.

Figs. 8, 9, 10 and 11 are fragmentary perspective views of alternate forms of the blades.

Referrlngto Figs. 1 and 2, 'the invention -'con.-' sists essentially of a blade supporting or holding member I and a blade member 2 Whichisslfidably and rigidly secured thereto by meansof 'ra locking device 3. The blade 2 is adaptedv to reside in a recessed groove 4 formed in the upper portion of the holder I and is held therein bythe slidable lock 3. The lock '3 has Van upwardly. extending arm 5 with a protrusion 6 thereon. The said blade member 2 has recessed'therein a transverse groove I0 which is engageable Iby the protrusion 6. The lower extremity of slidable lock member 3 has a threaded arm I I dependent therefrom which passes through a related iaper-v As 'shown in Fig; 3, the blade supportingfmem,

ber I hasformed therein plural grooves I 5 which are arranged diagonally on opposite sides `of Vthel member I. grooves I5 are of such proportion to provide a surface which is lparallel and whichlforms a 190 angle relative to the underside of the yblade Y2. The grooves I5 effectively trap .dust .ordirtthat may lodge on the machined part being measurd;

and thus avoid inaccurate measurements.

A further novel feature of vthe Aprecision tool is disclosed in the recesses 20. Asillustrated in Fig. 4, the external `manufactured part `=2| is to be measured for accuracy of .the angle .formed by the top and side thereof, and in doing sc a user would observe for the presence of light betweenY the blade 2 and the top of part 2| and the member I and the side of part 2|.. It is evident that the assembly must be held parallel to the leye and the recess 20, being cut away. facilitates the ob.- servation. Without the recess 20, conventional squares, not shown, limit the perception of light in that the corner of the square is shadowed by the extraneous edge of the square. It is apparent therefore, that anyone'utilizing the instant device may achieve a relatively greater degree of accuracy in measuring. As shown in Fig. 3, the recess l20 is cut back to a point 22 adjacent the underside of the blade 2, thereby permitting close inspection of the angle formed by the blade 2 and the related side of member I, and subsequently the accuracy of relationship between the external part and the square.

The lands I6 located .between the Alternate forms of the lands and grooves are illustrated in Figs. 5, 6 and 7. The groove 25, Fig. 5, is formed by sides 2E, 2l and provides a dust catching ledge at 30.

Fig. 6 illustrates a square-cut groove 3l having dust catching ledges 32, 33 thereon.

Fig. illustrates a groove 34 formed by inwardly slanting side walls 35, 36, the design of which increases the dust catching potentialities of the ledges 3l, 38 formed thereby.

Various types of slidable blade members could be utilized with the instant invention, as shown in Figs. 8, 9, 10 and ll, wherein a blade 43 having two oppositely positioned knife edges 4I, 42 thereon, is disclosed. Fig. 9 likewise discloses a blade 43 having a knife edge 44 and a fiat edge 45 thereon. In Fig. 10 the blade 46 has two oppositely positioned knife edges 4l, 48 thereon, differing from the aforementioned blade 40 in that the sides of the knife edges 4l, 43 are flat While the sides of the knife edges on blade 48 are curved.

Blade 50, Fig. 11, is analogous to blade 43 in that a flat edge 52 and a knife edge 5I is provided except the sides of edge I are flat while the sides of edge 44 are curved. The curved and fiat edges provide maximum ease of observation when employed in the manner best suited therefor.

It is proposed that inaccuracies due to the glare of reflected light be reduced to a minimum, by the coloring of all measuring surfaces of the blades. In this manner stray refiected light can be Vreadily differentiated from the observable light between the blade and the measured part. While manycoloring processes are available, it is preferred that the blades be colored by the well-known blueing process.

, It-is understood that while the inventiornas illustrated is applied to a holder having a slidablc blade therein, it could readily be applied to aholder having a fixed blade thereon.

While four specific forms or embodiments of the invention have been shown'` and described herein for illustrative purposes, and the construction and arrangement incidental to a specific application thereof have been disclosed and discussed in detail, it is to be understood that the invention is limited neither to the mere details or -relative arrangement of parts, nor to its speciiic embodiments shown herein. but that extensive deviations from the illustrated forms or embodiments of the invention may be made without departing from the principles thereof.

What `I claim is:

, l. A precision-type instrument of the class described including a blade, a blade holder and means for locking said blade in said holder, said blade holder having a plurality of grooves in plural Sides of said holder, plural lands formed thereby being of equal height to provide a flat plane, said holder further having plural recesses therein extending rearwardly to terminate adj acent the underside of said blade.

2. A precision-type instrument of the class described for indicating the relative flat surface of an external part including a blade, a blade holder and means for locking said blade in said holder, said blade holder having a plurality of dust catching grooves in at least one of the sides thereof, plural lands formed thereby adapted to present a flat surface to one side of said external part, and said grooves formed diagonally and parallel one to the other relative to said blade.

3. A precision-type instrument of the class described for indicating the relative hat surface of a machined part including a blade, a blade holder and means for locking said blade in said holder, said blade holder having a plurality of dustcatching grooves in at least one of the sides thereof, plural lands formed thereby adapted to present a fiat surface to one side of said machined part, and said grooves formed diagonally and parallel one to the other relative to said blade, said holder having a recess therein extending rearwardly to terminate adjacent the underside of said blade.

4. A precision-type instrument of the class described for indicating the relative flat surface of a machined part including a blade, a blade holder and means for locking said blade in said holder, and said holder having plural recesses formed in said holder extending rearwardly to terminate adjacent the underside of said blade adapted to permit a visual observation of said machined part relative to said blade and holder.

5. An improved precision-type instrument adapted to be employed as an inside and outside square, including a blade, a blade holder and means for locking said blade in said holder. means formed in said holder adapted to catch dust particles, and said latter means comprising pluralties of lands and grooves with the upper surfaces of the former terminating in the same plane.

PAUL JOHN BAUERLE.

REFERENCES CITED The following references are of record in the rile of this patent:

UNITED STATES PATENTS Number Name Date 761,707 Peyman June 7, 1904 794,031 Lehman July 4, 1905 1,446,679 Winiome Feb. 27.11923 1,488,401 McCracken Mar. 25, 1924 1,946,432 -Aldeborgh Feb. 6, 1934 2,315,004 Painter Mar. 30, 1943 2,491,672 Lowenstein Dec. 20, 1949 FOREIGN PATENTS Number Country Date 98,870 Sweden Mar. 14, 1940 

